Abstract: To provide a production technique for an edible egg that contains a sufficient amount of ergothioneine by using the biological accumulation of the ergothioneine in eggs, and that has antioxidative activity. This ergothioneine-containing egg is obtained from a hen raised by being fed a hen feed for a prescribed time period, the hen feed being manufactured by manufacturing the ergothioneine-containing extract solution from a waste medium used in the production of edible mushrooms and mixing a prescribed amount of the extract solution into a feed for the hen used generally.